How to make a screenshot of all the content of a Scrollview? - ios

Question

I want to create a screenshot of a UIScrollView which should contain the whole content of the scroll view, even that content, which is currently not visible to the user. For that I tried the following two methods:
func snapShot(view:UIView) -> UIImage {
UIGraphicsBeginImageContextWithOptions(view.bounds.size, true, 0);
view.drawViewHierarchyInRect(view.bounds, afterScreenUpdates: true);
let image = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return image;
}
func snapShotScrollView(scrollView:UIScrollView) -> UIImage {
let bounds = scrollView.bounds;
scrollView.bounds.size = scrollView.contentSize;
let image = snapShot(scrollView);
scrollView.bounds = bounds;
return image;
}
But the resulting image is still just showing those view elements inside the scroll view which are currently visible to the user. But I want to see all views.
How can I do that?
EDIT
I also tried:
func snapshot() -> UIImage? {
var image: UIImage?
UIGraphicsBeginImageContext(scrollView.contentSize)
let savedContentOffset = scrollView.contentOffset
let savedFrame = scrollView.frame;
scrollView.contentOffset = CGPoint.zero;
scrollView.frame = CGRect(x: 0, y: 0, width: scrollView.contentSize.width, height: scrollView.contentSize.height);
scrollView.layer.render(in: UIGraphicsGetCurrentContext()!)
image = UIGraphicsGetImageFromCurrentImageContext();
scrollView.contentOffset = savedContentOffset;
scrollView.frame = savedFrame;
UIGraphicsEndImageContext();
return image
}
Edit 2
My UIScrollView is placed inside a UIView and does contain a UIStackView. The View is designed as a popover view so that it looks like a dialogue is popping up. The code sample from my first edit is working in a blank UIViewController with only one UIScrollView but not in the mentioned constellation.

Answer 1

To Swift from this answer, adding a test ViewController:
class ScreenShotTestViewController: UIViewController {
var scrollView: UIScrollView!
override func viewDidLoad() {
super.viewDidLoad()
scrollView = UIScrollView(frame: CGRect(origin: CGPoint.zero, size: view.frame.size))
scrollView.contentSize = CGSize(width: view.frame.size.width, height: view.frame.size.height * 2)
scrollView.backgroundColor = UIColor.yellow
view.addSubview(scrollView)
let label = UILabel(frame: CGRect(x: 0.0, y: view.frame.size.height * 1.5, width: view.frame.size.width, height: 44.0))
label.text = "Hello World!"
scrollView.addSubview(label)
let screenShot = snapshot()
}
func snapshot() -> UIImage?
{
UIGraphicsBeginImageContext(scrollView.contentSize)
let savedContentOffset = scrollView.contentOffset
let savedFrame = scrollView.frame
scrollView.contentOffset = CGPoint.zero
scrollView.frame = CGRect(x: 0, y: 0, width: scrollView.contentSize.width, height: scrollView.contentSize.height)
scrollView.layer.render(in: UIGraphicsGetCurrentContext()!)
let image = UIGraphicsGetImageFromCurrentImageContext()
scrollView.contentOffset = savedContentOffset
scrollView.frame = savedFrame
UIGraphicsEndImageContext()
return image
}
}
Results in an image of the complete content, including subviews: